"What is wrong with people nowadays?" Futomaki manager Mercel Vuran said after she discovered the dead bird in their bins about 11am yesterday.
"It’s not just by accident; someone must have put it there."
Mrs Vuran notified the Department of Conservation (Doc), who identified the bird as a little penguin.
New Zealand Penguin Initiative penguin scientist Hiltrun Ratz said the incident was peculiar.
"Clearly, someone found it and thought to remove it, but why they decided to put it in a dumpster there’s no way of knowing."
Dr Ratz said the penguin looked like it had been moulting and someone may have put it in the bin thinking they were saving it from predators.
She said it was important to report sightings of dead penguins
"If we don’t know where and how penguins get themselves into trouble, we can’t protect them."
Doc said it was following up on the incident.